Glitter-Sized Photovoltaics Produce Competitive Results

Sandia National Laboratories has developed photovoltaic (PV) cells the size of glitter, potentially revolutionizing the way solar energy is collected and used. Sandia boasts possibilities for the technology, such as turning a person into a walking solar-battery charger if the cells were fastened to flexible substrates molded around clothing.

The cells are fabricated using microelectronic and microelectromechanical systems (MEMS) techniques common to today’s electronic foundries.

Sandia lead investigator Greg Nielson said the research team has identified more than 20 benefits of scale for its microphotovoltaic cells. These include new applications, improved performance, potential for reduced costs and higher efficiencies.

“Eventually, units could be mass-produced and wrapped around unusual shapes for building-integrated solar, tents and maybe even clothing,” he said.

This would make it possible for campers or military personnel in the field to recharge batteries for phones, cameras and other electronic devices as they walk or rest.

But how much do they cost? According to Sandia, the cells will eventually be less expensive and have greater efficiencies than current PV collectors that are pieced together with 6-in.-square solar wafers. Part of the potential cost reduction comes about because microcells require relatively little material to form well-controlled and highly efficient devices.

For large-scale power generation, one of the biggest benefits is a significant reduction in manufacturing and installation costs compared with current PV techniques, according to Sandia researcher Murat Okandan.

From 14 to 20 micrometers thick (a human hair is approximately 70 micrometers thick), the wafers are 10 times thinner than conventional 6-in.-by-6-in. brick-sized cells, yet they perform at about the same efficiency.

“So they use 100 times less silicon to generate the same amount of electricity,” Okandan said. “Since they are much smaller and have fewer mechanical deformations for a given environment than the conventional cells, they may also be more reliable over the long term.”

This development is good news for contractors looking to enter the solar-power market. Sandia’s PV cells eliminate some of the common drawbacks to solar technology, and it could lead to greater implementation.